With a presidential election looming this autumn, the forecast for federal funding for infrastructure is somewhat uncertain.

Too often infrastructure is among the issues drowned out by so-called moral issues and vague discussions of the economy.

Though project decisions and planning fall mainly to local governments and agencies, they often rely in part on federal funding. The two main presidential candidates have shared their plans for infrastructure development (see box), though in general both seem to fail to inspire voters.

This spring the Underground Construction Association (UCA) of SME hosted the World Tunnel Congress (WTC), in San Francisco. It was the first time in 20 years for the event to be held in the US, and marked the largest gathering of tunnel professionals in history. The consensus among industry leaders from across the US is that tunnelling has a lot to offer and will remain active. Much of the work currently underway or in the planning stages is related to transit, water and wastewater.

Measure up

Bill Hansmire, technical director of tunnelling for WSP Parsons Brinckerhoff, says “today Los Angeles has changed from being what you might perceive as highway-centric.”

Local highways such as the San Bernadino and the Santa Monica freeways have notorious traffic congestion, with which the city has had enough. In 2008 residents voted to approve a tax measure to fund more transit.

“Not just entirely rapid, but all forms of transit that work together,” Hansmire explains. “A lot of that is tunnels.

“Today there are major tunnel projects underway and these tunnels form what I think is the keystone. You can have lines coming up from the suburbs into the city but if they can’t get through the urban core, no one is going to take them.”

There is approximately USD 10bn in construction right now to build another 10 miles of underground transit, “and this 10bn will make a real difference,” he says.

He’s working on the Regional Connector – a 2-mile (3.2km) tunnel with three stations that will connect Los Angeles’ Blue and Gold Lines. The TBM should launch before the end of the year on this USD 1.5bn project. There is a TBM working on 1 mile of twin tunnels for the 8.5-mile (13.7km) Crenshaw/ LAX light rail line, which includes three underground stations.

There is also the three-phase, 9-mile (14.5km) Westside Subway Extension of the Metro Purple Line, estimated to cost USD 5.6bn. A JV of Skanska-Traylor-Shea, with lead designer Parsons Transportation Group, is the design-build contractor for the USD 1.6bn first phase of 3.9 miles with twin tunnels and three underground stations.

In November Los Angeles County will vote on another ballot measure for a half-cent sales tax increase to fund a major expansion of Southern California’s transportation infrastructure. Called one of the most ambitious in modern US history, the tax increase would generate at least USD 860M per year for street repairs, highway improvements and new rail construction.

The tax, which has no end date, would increase the county’s base sales tax rate to 9.5 per cent and push the rate to 10 per cent in some cities. If the tax were approved, two cents for every dollar spent in the county would fund transportation improvements. It will require a two-thirds’ vote to pass.

Waterways

This summer saw a milestone on the bottom of the Elizabeth River in Virginia. The Elizabeth River Tunnels Project Team, comprised of Elizabeth River Crossings OpCo, LLC, SKW Constructors, JV and the Virginia Department of Transportation (VDOT), opened one lane of the new, one-mile long, immersed Midtown Tunnel. Connecting the shorelines of Portsmouth and Norfolk, Virginia, crews immersed 11 elements, each made of 16,000t of reinforced concrete, starting in October 2014 and placing the final one last July. The two-lane road tunnel is part of the largest design-build project in the Hampton Roads region's history.

Hampton Roads refers to the area in the middle of the Eastern seaboard where the James, Nansemond and Elizabeth rivers pour into the mouth of the Chesapeake Bay. Some 1.6 million people live locally and rely on Virginia's existing Midtown Tunnel, which carries more than one million vehicles per month. Chesapeake Bay will also be the site of a new bored tunnel: the parallel Thimble Shoal Tunnel Project will construct a new milelong (1.6km), two-lane tunnel under the Thimble Shoal Channel. The new tunnel will carry two lanes of traffic southbound and the existing tunnel will carry two lanes of traffic northbound.

This summer the Chesapeake Bay Bridge-Tunnel (CBBT) awarded a contract to the design-build team of Dragados USA and Schiavone Construction Company, LLC, which submitted the lowest price proposal at USD 755,987,318. The JV bid the project as a TBM-mined tunnel, which will have an inner diameter of 39ft (11.9m). Maximum tunnel depth from the crown will be 105ft (32m) below the water surface and, and from the invert, 134ft (40.8m) below the surface.

Meeting Urban needs

Verya Nasri, gobal tunnel lead with Aecom, gladly reported at WTC that phase one of the largest infrastructure project in the US, has been executed on time and on budget with no major claim. The four-phase Second Avenue Subway is worth an estimated USD 17bn. Underground for their entire 8.5-mile length the Second Avenue Subway’s twin tunnels would run between Harlem in the north and Hanover Square in the south.

The first phase reaches completion this year, which is worth USD 4.5bn. He says of the project’s success, “it’s maybe not very common but it’s possible if the project is planned well; if we have a good partnership between the main players, owners, engineers, contractors; if we have good public relations and outreach with the community; and if we coordinate well from the beginning; then a large project like this can be successful even in the most difficult environment in the world.”

He’s speaking specifically of New York’s Upper East Side, “one of the densest urban environments in the world, probably the richest area in the United States, and being the place with the highest concentration of lawyers,” he jokes. “The importance of this particular project is that the only way you can build it is to tunnel. There isn’t any other solution.”

To meet the needs of the country’s largest metropolitan region tunnel projects are delivered not just for transit but also for water—through the New York City Department of Environmental Protection (DEP). In particular it has a program to repair the Delaware Aqueduct’s Rondout- West Branch Tunnel. A bypass tunnel and two deep shafts are currently underway.

Schiavone Construction Co. LLC, began work in 2013 on a contract to excavate two 30ft diameter shafts of 700ft and 900ft at each end of the tunnel alignment – one in the town of Wappinger, to the east, and one in the town of Newburgh, to the west. A JV led by Kiewit is using a TBM to mine the 12,500-long tunnel in rock.

Cleaning Up

In Indianapolis a recent economic impact study commissioned by Citizens Energy estimates that the utility provider will invest more than USD 4bn in its water, wastewater and natural gas systems from 2011-2025. The study estimates these investments will create or support 58,000 jobs in Indiana that will generate more than USD 450M of state and local taxes.

A large part of this is the DigIndy tunnel system, a 200ft (61m) deep, 28-mile (45km) network of sewers, 18ft (5.5m) in diameter. So far 10 miles have been excavated, and a JV of Shea/Kiewit secured a USD 500M contract this spring to complete the final 18 miles. The TBM is expected to re-launch this autumn